French to millimeters
Type a value in Fr to get it in mm instantly.
4.667mm
That's 1.75× as wide as an 8 Fr feeding tube, while a 16 Fr urinary catheter is 1.14× wider. Its circumference is about 14.66 mm.
Convert the other way: mm to Fr
What it means
How wide is that tube?
French gives the outer diameter. The inner lumen is smaller and depends on the wall thickness and material.
The math
How to convert Fr to mm
To convert French to millimeters, multiply by 0.333333.
Example: 14 Fr × 0.333333 = 4.66667 mm.
In the other direction, 1 mm = 3 Fr.
Every unit
That tube size in every unit
Tables
Fr to mm conversion table
| Fr | mm |
|---|---|
| 3 Fr | 1 mm |
| 4 Fr | 1.33333 mm |
| 5 Fr | 1.66667 mm |
| 6 Fr | 2 mm |
| 7 Fr | 2.33333 mm |
| 8 Fr | 2.66667 mm |
| 10 Fr | 3.33333 mm |
| 12 Fr | 4 mm |
| 14 Fr | 4.66667 mm |
| 16 Fr | 5.33333 mm |
| 18 Fr | 6 mm |
| 20 Fr | 6.66667 mm |
| 22 Fr | 7.33333 mm |
| 24 Fr | 8 mm |
| 28 Fr | 9.33333 mm |
| 30 Fr | 10 mm |
mm to Fr conversion table
| mm | Fr |
|---|---|
| 3 mm | 9 Fr |
| 4 mm | 12 Fr |
| 5 mm | 15 Fr |
| 6 mm | 18 Fr |
| 7 mm | 21 Fr |
| 8 mm | 24 Fr |
| 10 mm | 30 Fr |
| 12 mm | 36 Fr |
| 14 mm | 42 Fr |
| 16 mm | 48 Fr |
| 18 mm | 54 Fr |
| 20 mm | 60 Fr |
| 22 mm | 66 Fr |
| 24 mm | 72 Fr |
| 28 mm | 84 Fr |
| 30 mm | 90 Fr |
Quick answers
Quick answers
- How many mm is 1 Fr?
- 1 Fr is 0.333333 mm.
- How many mm is 10 Fr?
- 10 Fr is 3.33333 mm.
- How many mm is 14 Fr?
- 14 Fr is 4.66667 mm.
The units
About these units
French (Fr)
Outer diameter in thirds of a millimeter.
Millimeters (mm)
Outer diameter in millimeters.
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